kern.securelevel: 0 -> 1 creating runtime link editor directory cache. preserving editor files. starting network daemons: sshd. starting local daemons:. Tue Jul 9 08:57:37 PDT 2019 OpenBSD/amd64 (ci-openbsd-multicore-3.c.syzkaller.internal) (tty00) Warning: Permanently added '10.128.0.124' (ECDSA) to the list of known hosts. executing program login: panic: kernel diagnostic assertion "cpipe->pipe_buffer.cnt == 0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/sys_pipe.c", line 223 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 416932 27995 0 0x2 0 1 syz-executor1001 * 50835 27995 0 0x2 0x4000000 0K syz-executor1001 db_enter() at db_enter+0x18 panic() at panic+0x15c __assert(ffffffff81fac4df,ffffffff81f97e38,df,ffffffff81f4ba54) at __assert+0x2e pipespace(fffffd8074bd6b68,10000) at pipespace+0x18f pipe_write(fffffd8074bf1c78,ffff800020bbb368,0) at pipe_write+0x973 dofilewritev(ffff800020b618c0,4,ffff800020bbb368,0,ffff800020bbb470) at dofilewritev+0x1ac sys_write(ffff800020b618c0,ffff800020bbb408,ffff800020bbb470) at sys_write+0x83 syscall(ffff800020bbb4e0) at syscall+0x552 Xsyscall(6,0,31ad4d14138,0,31ad4d14118,31ad4d14110) at Xsyscall+0x128 end of kernel end trace frame: 0x31da0278a70, count: 6 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic kernel diagnostic assertion "cpipe->pipe_buffer.cnt == 0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/sys_pipe.c", line 223 ddb{0}> trace db_enter() at db_enter+0x18 panic() at panic+0x15c __assert(ffffffff81fac4df,ffffffff81f97e38,df,ffffffff81f4ba54) at __assert+0x2e pipespace(fffffd8074bd6b68,10000) at pipespace+0x18f pipe_write(fffffd8074bf1c78,ffff800020bbb368,0) at pipe_write+0x973 dofilewritev(ffff800020b618c0,4,ffff800020bbb368,0,ffff800020bbb470) at dofilewritev+0x1ac sys_write(ffff800020b618c0,ffff800020bbb408,ffff800020bbb470) at sys_write+0x83 syscall(ffff800020bbb4e0) at syscall+0x552 Xsyscall(6,0,31ad4d14138,0,31ad4d14118,31ad4d14110) at Xsyscall+0x128 end of kernel end trace frame: 0x31da0278a70, count: -9 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020bbb0e0 rbx 0xffff800020bbb190 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffffffff8129f2b3 kprintf+0x173 r9 0x1 r10 0xebcc0324f435994d r11 0x5e9058dc3d58bbc8 r12 0x3000000008 r13 0xffff800020bbb0f0 r14 0x100 r15 0x1 rip 0xffffffff81c0e2c8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020bbb0d0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor1001) pid=50835 stat=onproc flags process=2 proc=4000000 pri=16, usrpri=53, nice=20 forw=0xffffffffffffffff, list=0xffff800020b60c68,0xffffffff823aadc0 process=0xffff800020b2b890 user=0xffff800020bb6000, vmspace=0xfffffd806e7e0cf8 estcpu=3, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 27995 416932 47164 0 7 0x2 syz-executor1001 27995 408787 47164 0 2 0x4000002 syz-executor1001 27995 264224 47164 0 2 0x4000002 syz-executor1001 *27995 50835 47164 0 7 0x4000002 syz-executor1001 47164 479012 10813 0 3 0x10008a pause ksh 10813 389890 75096 0 3 0x92 select sshd 30328 4483 1 0 3 0x100083 ttyin getty 75096 136739 1 0 3 0x80 select sshd 17758 131227 77225 74 3 0x100092 bpf pflogd 77225 314754 1 0 3 0x80 netio pflogd 41468 402788 81494 73 3 0x100090 kqread syslogd 81494 345563 1 0 3 0x100082 netio syslogd 38192 137329 1 77 3 0x100090 poll dhclient 1924 3379 1 0 3 0x80 poll dhclient 3967 89463 0 0 3 0x14200 pgzero zerothread 41531 108612 0 0 3 0x14200 aiodoned aiodoned 70809 307534 0 0 3 0x14200 syncer update 71607 372936 0 0 3 0x14200 cleaner cleaner 97917 476194 0 0 3 0x14200 reaper reaper 94743 475458 0 0 3 0x14200 pgdaemon pagedaemon 30618 160213 0 0 3 0x14200 bored crynlk 13818 90235 0 0 3 0x14200 bored crypto 58229 159970 0 0 3 0x40014200 acpi0 acpi0 71179 265649 0 0 3 0x40014200 idle1 42230 354849 0 0 3 0x14200 bored softnet 2391 144984 0 0 3 0x14200 bored systqmp 20466 248695 0 0 3 0x14200 bored systq 75734 174105 0 0 3 0x40014200 bored softclock 66857 68618 0 0 3 0x40014200 idle0 12798 117740 0 0 3 0x14200 bored smr 1 456409 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 27995 (syz-executor1001) thread 0xffff800020b618c0 (50835) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff823a5968) #0 witness_lock+0x52e #1 __mp_acquire_count+0x51 #2 mi_switch+0x38f #3 sleep_finish+0x113 #4 tsleep+0x198 #5 pipe_write+0x8f0 #6 dofilewritev+0x1ac #7 sys_write+0x83 #8 syscall+0x552 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9452 6383K 6384K 78643K 10539 0 0 pcb 25 9K 9K 78643K 57 0 0 rtable 61 2K 2K 78643K 125 0 0 ifaddr 25 7K 7K 78643K 26 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1467 0 0 iov 0 0K 12K 78643K 1 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1181 74K 74K 78643K 1186 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 1K 78643K 2 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 2 0K 0K 78643K 2 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 1 0K 0K 78643K 1 0 0 proc 52 50K 58K 78643K 334 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 in_multi 11 0K 0K 78643K 11 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 18 79K 79K 78643K 18 0 0 exec 0 0K 1K 78643K 179 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 66 11K 11K 78643K 821 0 0 UVM aobj 2 2K 2K 78643K 2 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 NDP 4 0K 0K 78643K 4 0 0 temp 39 2728K 2792K 78643K 1993 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 2 0 0 1 0 1 1 0 8 0 inpcbpl 280 29 0 23 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 23 0 1 1 0 1 1 0 8 0 syncache 264 5 0 5 1 0 1 1 0 8 1 tcpcb 544 8 0 5 1 0 1 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 8 0 0 1 0 1 1 0 8 0 pfstkey 112 8 0 0 1 0 1 1 0 8 0 pfstate 328 8 0 0 1 0 1 1 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 96 0 0 6 0 6 6 0 8 0 art_table 32 97 0 0 1 0 1 1 0 8 0 art_node 16 22 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1401 0 17 45 0 45 45 0 8 0 ffsino 272 1401 0 17 93 0 93 93 0 8 0 nchpl 144 1575 0 32 58 0 58 58 0 8 0 uvmvnodes 72 1411 0 0 26 0 26 26 0 8 0 vnodes 200 1411 0 0 75 0 75 75 0 8 0 namei 1024 3645 0 3645 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 2458 0 2458 2 1 1 2 0 8 1 plimitpl 152 15 0 8 1 0 1 1 0 8 0 sigapl 432 205 0 193 2 0 2 2 0 8 0 knotepl 112 5 0 0 1 0 1 1 0 8 0 kqueuepl 104 1 0 0 1 0 1 1 0 8 0 pipepl 112 136 0 127 2 1 1 1 0 8 0 fdescpl 488 206 0 193 3 0 3 3 0 8 0 filepl 152 987 0 935 2 0 2 2 0 8 0 lockfpl 104 7 0 6 2 1 1 1 0 8 0 lockfspl 48 4 0 3 2 1 1 1 0 8 0 sessionpl 112 19 0 9 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 52 0 43 1 0 1 1 0 8 0 zombiepl 144 193 0 193 2 1 1 1 0 8 1 processpl 896 221 0 193 4 0 4 4 0 8 0 procpl 632 224 0 193 3 0 3 3 0 8 0 sockpl 384 73 0 55 2 0 2 2 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 67 0 0 9 0 9 9 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 86 0 0 6 0 6 6 0 8 0 bufpl 256 2241 0 276 123 0 123 123 0 8 0 anonpl 16 20337 0 18767 8 1 7 7 0 125 0 amapchunkpl 152 543 0 500 2 0 2 2 0 158 0 amappl16 192 99 0 76 2 0 2 2 0 8 0 amappl14 176 38 0 34 1 0 1 1 0 8 0 amappl12 160 7 0 7 1 0 1 1 0 8 1 amappl11 152 47 0 32 1 0 1 1 0 8 0 amappl10 144 55 0 53 1 0 1 1 0 8 0 amappl9 136 427 0 426 1 0 1 1 0 8 0 amappl8 128 102 0 97 1 0 1 1 0 8 0 amappl7 120 20 0 18 1 0 1 1 0 8 0 amappl6 112 46 0 42 1 0 1 1 0 8 0 amappl5 104 140 0 127 1 0 1 1 0 8 0 amappl4 96 474 0 449 1 0 1 1 0 8 0 amappl3 88 157 0 145 1 0 1 1 0 8 0 amappl2 80 802 0 740 2 0 2 2 0 8 0 amappl1 72 13801 0 13351 16 6 10 16 0 8 0 amappl 80 424 0 400 1 0 1 1 0 84 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma64 64 259 0 259 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 206 0 193 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 206 0 193 1 0 1 1 0 8 0 vmmpekpl 168 5567 0 5545 2 0 2 2 0 8 0 vmmpepl 168 29476 0 28559 52 12 40 52 0 357 0 vmsppl 368 205 0 193 2 0 2 2 0 8 0 pdppl 4096 419 0 386 5 0 5 5 0 8 0 pvpl 32 80677 0 77352 31 3 28 28 0 265 1 pmappl 232 205 0 193 1 0 1 1 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 256 0 4 8 0 8 8 0 8 0